RU2257965C1 - Installation for cleanout of surfaces of the complex form items - Google Patents

Abstract

FIELD: equipment for cleanout of dirty surfaces of the complex form items.

SUBSTANCE: the invention is pertinent to the field of cleanout of dirty surfaces of the complex form items, for example rails. The installation consists of a furnace with a fluidized layer containing adjacent chambers separated by a partition with a overflow slit in its lower part, one of which has a gate; air inlet, and also has a gas-distribution grating, an undergrating chamber, electrical heaters and a heater of air. On the gas-distribution grating there are caps for a spouting fluidization of the boiling layer in a stringently determined place in respect to the cleaned out surfaces of items and on the way of the quick raise of the abrasive particles are mounted. Deflectors- refractors of the up-coming stream of particles. The invention allows to ensure a directed heat and abrasive action of directional thermal and abrasive action of a fine grain material on a surface of an item, quick changeover of the spent abrasive material by a new pure portion and so to increase productivity of the process and to improve the quality of cleanouts of dirty surfaces.

EFFECT: the invention ensures an increased productivity of the process, to increase quality of cleanout of the dirty surfaces.

3 cl, 1 dwg

Description

The installation for cleaning the surfaces of products of complex shape is intended for use in the field of cleaning contaminated surfaces, for example, for surface cleaning of contaminated rails during their restoration, which consists in heating the rail surfaces to the melting temperature of the organic components of the contaminants, followed by sandblasting with compressed air and a fluidized-bed abrasive.

Known heating installation for heat treatment, containing a hoist of parts and sequentially installed heating chamber for hardening, hardening chamber, heating chamber for tempering and cooling chamber for tempering [1]. In this installation, a fluidized-bed furnace is used as a heating device, providing uniform and quick heating of the workpieces.

This installation cannot be used to clean the surfaces of the rails, since the design of the furnace provides for loading and unloading of heated products into a fluidized bed on top of the heating chamber. This takes a large amount of time, which inevitably causes a cold part. In addition, in furnaces with unloading parts through the top, it is difficult to use the heat of the exhaust gases, since a heat exchanger cannot be installed above the layer, and the movable cover of the furnace, which reduces heat loss by radiation from the hot layer to the environment, complicates the design and operation of the furnace. Losses will also increase with increasing dimensions of the products being cleaned.

Also known is a furnace for heating and heat treatment of metal in a fluidized bed, containing adjacent chambers separated by a vertical partition with a transfer slot near the gas distribution grid [2].

In this furnace, operations of loading and unloading products are carried out through loading windows in the walls of the furnace. This allows you to translate through the fluidized bed furnace products of any length, install a heat exchanger and a cover over the layer, which reduces heat loss by radiation from the hot layer into the environment.

In addition, a fluidized bed furnace is known in which one of the adjacent chambers is equipped with a gate, which allows changing the level of the fluidized bed in the chambers [3].

However, with a constantly open slit, "working wear" of all the fine-grained material in the volume of both chambers occurs, that is, grain grinding to a dust-like state with loss of effective heat-transfer agent quality and layer contamination with grease and mechanical defects of the surfaces of the processed products. In addition, the replacement of fine-grained material, heating a new volume of the abrasive layer requires a significant investment of auxiliary time.

The purpose of the invention is to improve the quality of cleaning contaminated surfaces of products of complex shape due to the directed power, heat and abrasive effects of fine-grained material on the surface of the products and to ensure quick change of the spent volume of the layer with a new clean portion of fine-grained material, previously heated to operating temperature.

This goal is achieved by the fact that in the gas distribution grill there are caps of a gushing fluidization of a fluidized bed in a strictly defined place relative to the surfaces to be cleaned, and reflective refractors of an upward flow of particles are installed on the path of the rapid rise of abrasive particles. Slots-nozzles are made in the reflector-refractors for directional supply of compressed air heated to the working temperature under pressure, and shutters are installed in the holes for removing the spent material from the working chamber and in the transfer gap under the inter-chamber partition.

The drawing shows an installation for cleaning surfaces of products of complex shape.

In this installation, a fluidized-bed furnace is used as a heating device, providing uniform and quick heating of the workpieces. The furnace has two communicating chambers with a layer of fine-grained material - a preparatory chamber 1 and a working chamber 2, separated by a vertical partition 3 with a gap near the gas distribution grill, closed by a shutter 4 for bypassing the fluidized bed; gas distribution grill 5; sublattice chamber (collector) 6. In the gas distribution grill, on the side of the working chamber, caps of the gushing fluidization of the fluidized bed 7 are installed and openings for removal of waste material are made, which are closed by shutters 8 on the collector side. Reflector-refractors 9 are installed symmetrically with respect to the product to be cleaned, in which slit nozzles are made 10. The preparation chamber is hermetically closed by a cover 11, in which a window for the passage of gas is made, covered by a gate 12. An air heater coil 13 passes in the superlayer space of the furnace. the layer is heated by an electric heater 14.

Installation works as follows.

Air through the air heater 13 is fed into the sublattice chamber 6 and through the gas distribution grill 5 enters the furnace. In the initial state of the installation before the working start when the gate 12 is open, when the superlayer spaces of the preparatory and working chambers are connected, the height of the fluidized bed is the same in both chambers (shown by a dotted line). The product 15, fed into the furnace through the windows in the walls, passes between the reflective refractors. Then the window for the passage of gases in the lid 11 of the preparatory chamber is closed by a gate 12, as a result of which the air pressure in the superlayer space of this chamber rises, and the fine-grained material 16 is forced into the working chamber through a slot in the vertical partition 3 when the shutter 4 is open, occupying the position 17 over the product. After that, the shutter 4 closes, the gate 12 opens, and the preparation chamber through the pipe 18 is filled with a new volume of abrasive material equal to the filling volume of the working chamber, followed by heating to operating temperature.

The caps of the gushing liquefaction 7 create a stream of rapidly rising particles of fine-grained material, which bends around the reflector-refractors 9, and is sent to the cleaning zone. From the nozzle slots 10 in the direction of the surface to be cleaned, pressurized air comes out, heated to a working temperature, which carries the reflected abrasive particles with it, which helps to increase the mechanical effect of the particles on the surface of the product and improve the quality of cleaning.

The surface of the product being cleaned is heated to the melting temperature of the organic components of the contaminants (250 ... 350 ° C). In this case, a gradual contamination of the fine-grained material occurs.

To ensure quick removal of the spent abrasive material, the flaps are opened 8. The filling of the working chamber volume with a new clean portion of fine-grained material occurs through the transfer slot with the shutter 12 closed and the shutter 4 open.

Sources of information

1. Baskakov A.P. High-speed non-oxidizing heating and fluidized bed heat treatment. - M.: Metallurgy, 1968.

2. A.S. 193559 USSR, IPC C 21d, cl. 18s 9/00, 18s 9/70. Fluidized bed heating furnace. / N.I. Syromyatnikov, 1966.

3. A.S. 863977 USSR, M. cl. F 27 B 15/00. Fluid bed furnace. / A.P. Baskakov, N.F. Filippovsky, A.A. Zharkov et al., 1979 (prototype).

Claims (3)

1. Installation for cleaning contaminated surfaces of products of complex shape, for example, rails, consisting of a fluidized-bed furnace containing adjacent chambers separated by a partition with a recess gap in its lower part, one of which is equipped with a gate, as well as a gas distribution grill, sublattice chamber, electric heaters and an air heater, characterized in that, in order to improve the quality of cleaning contaminated surfaces due to the directed thermal and abrasive effects of fine-grained material on the surface , in the gas distribution grid there are installed caps of a gushing fluidization of a fluidized bed in a strictly defined place relative to the surfaces of the product being cleaned, and reflective refractors of an upward flow of particles are installed on the path of rapid lifting of abrasive particles. 2. Installation for cleaning contaminated surfaces of products of complex shape according to claim 1, characterized in that, in order to increase the mechanical effect of abrasive particles on the surface of the product, slots-nozzles are made in the reflector-refractors for directed supply of compressed air heated to working pressure temperature. 3. Installation for cleaning contaminated surfaces of products of complex shape according to claim 1, characterized in that, in order to ensure a quick change of spent abrasive material with a new clean portion, shutters are installed in the holes for removing spent material from the working chamber and in the transfer gap under the inter-chamber partition .